Reps from the nonprofit group Center for Auto Safety believe this is a new issue unrelated to the engine defect. They've counted nearly 400 non-collision "fire-and-near-fire" incidents - data they gathered from the National Highway Traffic Safety Administration, and its own findings.

The center has petitioned the NHTSA to demand a new recall.

"What they should be doing is opening a new investigation into why Kias and Hyundais are catching fire," Jason Levine of the Center for Auto Safety said.

But the NHTSA isn't investigating the issue yet. By law, it's required to respond to the Center's petition, and it has a few more weeks to do that.

As for the car makers, in statements to NBC Los Angeles, Hyundai said:

If it and the NHTSA "....Finds that additional remedies are warranted...We will take action."